An amorphous carbon film such as a diamond-like carbon film (abbreviated as “DLC film”) is excellent in abrasion resistance, slidability and strength. Therefore, amorphous carbon films are used in various fields, e.g., for protective films of various devices such as cutting tools and molds. Also, amorphous carbon films are formed on the surface of resin films or resin bottles formed of high polymer materials to serve as H2O and O2 gas barrier films. Particularly, it is desired that a water- and oil -repellent layer provided on a protective film formed of an amorphous carbon film should provide excellent abrasion resistance and slidability, as well as water- and oil-repellence that inhibits adsorption of water molecules (H2O) on the surface causing stains and degraded gas barrier effect.
For example, Japanese Patent Application Publication No. H06-215367 (“Patent Literature 1”) relates to a protective layer of a magnetic storage medium and discloses irradiating a hard carbon protective layer with a neutral radical species (atomic gas) generated by corona discharge, followed by forming a layer including a fluorine-containing lubricant having at least one polar group. Further, Japanese Patent Application Publication No. 2001-266328 (“Patent Literature 2”) discloses treating an amorphous hard carbon film surface with nitrogen plasma thereby to produce a carbon protective film containing 6 to 20 at % nitrogen within 30 Å from the surface and forming a fluorine-based lubricant layer on the carbon protective film.
Meanwhile, Japanese Patent No. 2889116 (“Patent Literature 3) discloses mixing silicon and nitrogen into an amorphous hard carbon film layer to produce an amorphous hard carbon film having excellent adhesion with a substrate and improved lubrication characteristics such as slidability and abrasion resistance. Additionally, Japanese Patent Application Publication No. 2010-67637 (“Patent Literature 4”) discloses a method for affixing an adhesive agent formed of a resin on the surface of an amorphous carbon film having poor adhesion. The Patent Literature 4 discloses forming silanol groups by oxidizing the surface of an amorphous carbon film containing silicon with ultra-violet rays, followed by reacting the silanol groups with Si—OR (wherein R is a methyl group or an ethyl group) groups contained in an adhesive, and affixing the adhesive on the surface of the amorphous carbon film containing silicon via a coupling agent.